Microfabrication techniques of a semiconductor, a magnetic film, and so on have been investigated•developed. For example, for a semiconductor element, processing of 20 nm or less has been required. Further, in a magnetic recording device (HDD), a technique of making a recording medium (a patterned media) by microfabricating a magnetic dot array has been considered in order to achieve terabit-class high density.
Here, development of forming a pattern by utilizing phase separation of a block copolymer has been made. For example, a dot pattern can be formed by phase separating a block copolymer of polystyrene and polymethyl methacrylate. By using the dot pattern as an etching mask of magnetic film, the magnetic dot array and the like can be made possible.
However, in a conventional technique, it become difficult to form a small pattern less than 20 nm.